Mikel Arteta made the painful discovery that Arsenal's old habits die as hard as his homecoming party was transformed into a wake in a matter of four painful minutes.
Arteta, returning to Arsenal as manager after retiring as a player with the club in May 2016 and just two weeks after watching from the away bench as former club Manchester City destroyed the Gunners here, made a low-key entrance.
There was no fanfare or formal introduction as Arteta acknowledged polite applause from the fans surrounding his technical area before taking his position on the touchline.
Arsenal supporters will be watching keenly to detect vital signs of what Arteta has soaked up from master coach and close friend Pep Guardiola during three full seasons at City that brought two Premier League titles and a historic domestic treble that included the FA Cup and Carabao Cup last term.
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There are outward signs such as the micro-management, attempting to orchestrate moves and positions by use of animated gestures and arm-waving tic-tac, and the smart-casual touchline attire.
And what he clearly wants most, like Guardiola, is intensity and energy in every moment and action.
He delivered the mantra in his match notes as he wrote: "In my mind, energy is everything. In life, in football and in sports."
It was what he got from Arsenal for the first 30 minutes as they ran all over a dishevelled Chelsea, Arteta conducting from the margins, his demands reflected in the work-rate of goalscorer Pierre-Emerick Aubameyang as he chased back to tackle near his own penalty area to a standing ovation.
And then there was the enigmatic Mesut Ozil, victim of harsh words from caretaker manager Freddie Ljungberg and presented with "a clean slate" by Arteta.
Ozil ran tirelessly and it was a sharp contrast to the last time he was substituted and walked past Arteta when he was replaced here after 76 minutes. This time he was warmly applauded for his efforts as opposed to feeling venom and lashing out at his own gloves with a boot in frustration.
Arteta appreciated Ozil's efforts but the trick is to get him on repeat. Easier said than done.
There may be a question of whether Arteta withdrew Ozil too early with Arsenal ahead but in reality he had tired and the introduction of the energetic Joe Willock was understandable.
The hard evidence of Arsenal's two most high-profile players prepared to do the dirty work is certainly early credit in the bank for Arteta.
If he can get them to buy into the Arsenal team ethic on a regular basis then that is a good platform for progress.
Arsenal's new manager was certainly not accompanied by Lady Luck on his return and he was not helped by an early injury to Calum Chambers, which saw Shkodran Mustafi introduced.
The tactical adjustment was easy but the personnel change was not, Mustafi culpable as he was turned far too easily for Tammy Abraham's winner.
As Chelsea started to dominate after the break, Arteta became even more animated, almost threatening to put tackles in himself on a couple of occasions as he strayed dangerously close to the touchline in his determination to get his message across.
And then, just as Arteta and Arsenal's hugely supportive fans were starting to think of a morale-boosting victory with seven minutes remaining, home keeper Bernd Leno took a hand - or to be more precise did not take a hand.
The goalkeeper needlessly flew out in "Superman" pose but got nowhere near Mason Mount's free-kick, leaving Jorginho with a simple tap-in.
Arteta turned away in anguish, his face buried in his palms with a mixture of incredulity at Leno's hapless non-intervention and a sense of injustice.
Jorginho was very fortunate to still be on the pitch after somehow escaping a second yellow card for a foul in the centre circle having been cautioned earlier.
Chelsea manager Frank Lampard admitted Jorginho may have got lucky - and so he was. Arteta will look back on this as a turning point.
Arsenal's players were clearly deflated by the manner of Chelsea's equaliser having worked so hard to keep them at bay, with even the sometimes liability David Luiz leading by example with some crucial interventions.
Abraham's decisive strike was the final insult.
If Arteta needs any further early lessons in what he must do, Mustafi provided him with one with the poor defending that lead to Chelsea's decisive second.
He will surely be in urgent discussions with Arsenal's recruitment team to find a central defender of steel and reliability as Luiz cannot be relied upon and Mustafi's vulnerability is unsustainable if Arteta is to build the side he wants.
Arteta looked downcast at the final whistle as he moved among his players, consoling them before taking the applause from supporters disappointed at the outcome but encouraged by the effort.
It is, of course, Arteta's honeymoon period and he will get the time, patience (and hopefully financial support) to address the situation of an Arsenal team who are now 11 points off the Champions League positions in 12th place.
Arteta has only one point from his first two games but this frustrating, infuriating, unlucky 90 minutes will only have confirmed what he and Arsenal already knew - this is no quick-fix job.